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3 votes
What numbers add to 2 and multiply to -56

User Picsoung
by
8.4k points

2 Answers

2 votes
-x² + 2x - 56 = 0

Use the quadratic formula to get the roots:


x = (-b\pm √(b^2-4ac))/(2a) where the equation is ax² + bx + c =0


(-b \pm √( b^2 -4( a)(c)) )/(2(a))\\\\ (-2\pm √(2^2 -4(-1)(56)) )/(2(-1))\\ \\(-2\pm √(228 ) )/(-2) = (-2\pm √(4*57 ) )/(-2) \\\\ = (-2\pm 2√(57 ) )/(-2) \\\\ = (-1\pm 1√(57 ) )/(-1) \\\\ =\boxed{\bf{ 1\pm √(57 ) }}\\a

The two numbers that add up to 2 and multiply to -56 are 1 + √57 and 1 - √57.
User TFBW
by
7.8k points
3 votes

The numbers are irrational, so they can't be exactly written down
using only digits.

In exact form, they are

1 + √57
and
1 - √57 .

In rounded form, they are

8.54983
and
-6.54983 .
User Sharath
by
7.2k points